Image copyright St Louis Police Image caption Missouri Governor Eric Greitens was taken into custody on Thursday

Missouri Governor Eric Greitens has been charged with felony invasion of privacy in connection with an inquiry into his extramarital affair.

The woman alleges that he tied her up, photographed her and threatened to release the image if she ever revealed their trysts.

The Republican, who was taken into custody on Thursday, says he made mistakes but "did not commit a crime".

Mr Greitens admitted last month he had a relationship with his hairdresser.

Critics have called his alleged actions "revenge porn" and blackmail.

Officials probe US governor for 'blackmail'

The charge sheet alleges Mr Greitens took a picture of the unidentified woman in "full or partial nudity" without her knowledge or consent.

Image copyright Facebook Image caption The Missouri governor with his wife, Sheena Greitens, and children

It further alleges that he transmitted the image "in a manner that allowed access to that image via a computer".

St Louis Circuit Attorney Kim Gardner vowed in a statement on Thursday to "hold public officials accountable in the same manner as any other resident".

In a statement, Mr Greitens said that he made a mistake but "did not commit a crime", and accused Ms Gardner of playing politics.

"With today's disappointing and misguided political decision, my confidence in our prosecutorial system is shaken, but not broken," Mr Greitens said.

"I know this will be righted soon. The people of Missouri deserve better than a reckless liberal prosecutor who uses her office to score political points."

Ms Gardner's spokeswoman, Susan Ryan, responded: "Despite the Governor's personal attacks, the Circuit Attorney believes the courtroom is the appropriate place to argue the facts, not the media."

Several state lawmakers have repeated calls for the governor to immediately resign.

Democratic state Senator Jamilah Nasheed of St Louis said: "Missourians thought they voted for a person of character and integrity, and instead they got a liar and alleged criminal."

Image copyright Eric Greitens for Governor Image caption The ex-Navy Seal ran as a conservative 'family man' during his successful 2016 campaign

The woman's then husband secretly recorded her in March 2015 describing the otherwise consensual encounter at Mr Greitens' home in the city of St Louis.

She told her now ex-husband in the audio recording that she "saw a flash through the blindfold and he [Mr Greitens] said, 'You're never going to mention my name'".

A lawyer for the unnamed man also alleges his then wife was slapped by Mr Greitens during a 2015 encounter in hospital as Mr Greitens' own wife was giving birth.

"When she admitted that she'd had sexual relations with her husband during a period of reconciliation, the governor slapped her," attorney Albert Watkins told CBS News last month.

Image copyright Missouri Governor's Office Image caption A lawyer for the governor says the allegations are politically motivated.

In January Mr Greitens acknowledged the affair, saying he had made "a personal mistake" and was "sorry for the pain it caused to everyone impacted".

He said he and his wife, Sheena Greitens, were moving on from the episode and wanted to deal with it privately.

Mr Greitens, a former special forces soldier and father-of-two, took office in 2016 with a pledge to tackle corruption.

He described himself during his campaign as a "Navy SEAL, native Missourian and most importantly, a proud husband and father".