Turkish authorities were planning a major shake-up of the military to remove elements linked to US-based preacher Fethullah Gulen just ahead of the failed coup, a key minister said Wednesday.

Energy Minister Berat Albayrak, who is the son-in-law of President Recep Tayyip Erdogan, suggested parts of the military had wanted to act against the government as they knew they were about to be purged.

Albayrak, who was with Erdogan throughout the night of the botched putsch on July 15, said the president had first been warned about the coup by a civilian and it was only later that the gravity of the situation became clear.

In his first meeting with foreign reporters since the coup night, Albayrak revealed that Turkey's Supreme Military Council (YAS) had this summer been planning to meet to expel all officers linked to Gulen, who Turkey blames for masterminding the putsch.

"They were going to take really important steps to remove Gulenist officers and generals from the armed forces. We were already working on this."

He said this would have been part of a general purge against pro-Gulen elements that would have also extended to the legal system and other institutions.

"These people (linked to Gulen) were detected and the related lists had been conveyed to the line ministries."

He added: "After they (the plotters) realised things were going like this, at their last breath, they took their final step (the coup)."

- 'A coordinated coup' -

He said only a small proportion of the NATO member's 750,000-strong military supported the coup but alleged pro-Gulen figures had successfully infiltrated the high and middle ranks in large numbers.

"If we are speaking especially at the level of general we understand the level of the problem."

Albayrak, who is married to Erdogan's eldest daughter Esra, was with the president at the holiday resort of Marmaris in southwestern Turkey when they received news of the coup.

"We received the first phone call from a civilian from the Istanbul area -- you cannot rationalise something based on one phone call," he said.

It was only after Erdogan could not reach important figures like chief of staff Hulusi Akar -- who had been abducted -- that the gravity of the situation became clear.

"We had phone calls with ministers and we realised this was not a simple thing but a coordinated coup d'etat," Albayrak said.

He said the president then spoke to Turkish media from his hotel but because some media -- such as state-run TRT -- had been taken over by the plotters the remarks were not broadcast.

"So Turkey did not hear us," he said.

It was at this point that, through FaceTime and using channels that had not been taken over, Erdogan made his now famous call to citizens to defeat the coup, Albayrak explained.

"This was one of the most important turning points," he said, recalling how crowds of Erdogan supporters then poured onto the streets to defeat the rebels.

The president then decided to fly back to Istanbul from the nearby airport of Dalaman to direct measures to stop the coup.

"Until the last minute it was not clear which place we were going to choose" to fly back from, Albayrak said.

Turkey PM warns post-coup crackdown not over
Ankara (AFP) July 27, 2016 - Turkey's prime minister warned Wednesday that the crackdown following a failed coup was not over, as authorities issued arrest warrants for dozens of former newspaper staff.

A senior minister also revealed that a major army shake-up had been planned just before the putsch -- suggesting elements in the military made the dramatic move because they knew they were about to be purged.

Since the attempted power grab on the night of July 15, more than 15,000 people have been detained and more than 8,000 of them remain in custody, according to the latest interior ministry figures.

"The investigation is continuing, there are people who are being searched for. There could be new apprehensions, arrests and detentions," Prime Minister Binali Yildirim told Sky News, according to the network's translation of his remarks.

"The process is not completed yet," he said.

In the attempted coup, renegade soldiers sought to topple President Recep Tayyip Erdogan but were stopped by crowds of civilians and loyalist security forces.

At least 270 people were killed on both sides.

Turkey blames the botched putsch on US-based preacher Fethullah Gulen, who strongly denies the accusations and demands that the United States resist calls for his extradition.

But Yildirim said Turkey was "determined" to secure his removal.

"We shared all the details with them and, from this point on, the task falls on the shoulders of the US government," the prime minister said.

- 'Planned purge' -

Energy Minister Berat Albayrak, who is Erdogan's son-in-law, said Turkish authorities had been planning a major purge of the military and other institutions to remove Gulen-linked elements ahead of the coup attempt.

"They were going to take really important steps to remove Gulenist officers and generals from the armed forces. We were already working on this," said Albayrak, who was with Erdogan on the coup night.

Turkey on Wednesday issued arrest warrants for 47 former staff of the once pro-Gulen Zaman newspaper suspected of links to the reclusive cleric.

An official who declined to be named said the swoop covered "executives and some staff including columnists", describing Zaman as the "flagship media organisation" of the Gulen-led movement.

In March, Zaman and its English-language sister newspaper Today's Zaman were taken over by state-appointed administrators and it has since taken a strongly pro-government line.

Several former staff are believed to have since left Turkey.

The official insisted the warrants were not related to what individual columnists had previously said or written.

But "prominent employees of Zaman are likely to have intimate knowledge of the Gulen network and as such could benefit the investigation", the official explained.

Earlier in the week, Turkey issued another 42 arrest warrants for journalists, 16 of whom have so far been detained according to state-run news agency Anadolu.

- Military reshuffle -

A large-scale shake-up of the Turkish armed forces is expected to be announced when the country's Supreme Military Council meets on Thursday.

More than 10,000 soldiers and around half of the 358 generals serving in Turkey have been detained, leaving gaping holes in the command structure to be filled.

Tens of thousands of Turkish civilians have lost their jobs since July 15.

The first worker in the private financial sector to be affected is AK Investment's research director Mert Ulke, after the financial regulator cancelled his licence following his report on the failed coup.

UN Secretary-General Ban Ki-moon on Wednesday expressed deep concern about the ongoing wave of arrests in Turkey following the putsch.

The EU meanwhile appointed a new ambassador to Turkey and repeated warnings that Ankara must respect democracy and human rights for ties to prosper.