Actress Lena Headey, who plays Cersei Lannister on the hit series Game of Thrones, has had her impressive pay cheque revealed during a child custody battle with her ex-husband.

Peter Loughran and Lena Headey in 2009. Photo: Getty

Headey and Irish musician Peter Loughran are locked in a legal fight over their six-year-old son Wylie, with Loughran demanding Headey pay his £31,000 ($A52,529) in legal fees.

According to TMZ, Loughran has claimed in legal documents Headey should cover the fees because he is unemployed, while she is earning a large sum of money for her role on the HBO show.

In November The Hollywood Reporter claimed Headey and co-stars Peter Dinklage, Kit Harington, Emilia Clarke and Nikolaj Coster-Waldau banded together to negotiate a pay rise — upping their fee to $US1.1million ($A1.49 million) an episode each.

Loughran’s filing reportedly confirms Headey has recently received a pay rise.

Headey is fighting for her and Loughran’s custody agreement to be modified in order for her to take Wylie with her to the United Kingdom while she films Game of Thrones.

Loughran has argued this would take his son away from him.

Although Loughran has claimed Headey’s filming commitments for this year should be finished, she recently produced a letter from the show’s producer requesting her presence on set through to February 2017.

Headey has also claimed she pays Loughran $US10,000 ($A13,500) a month in child support despite him rarely seeing Wylie in recent months.

The judge is yet to rule on both Headey and Loughran’s requests.

The pair were married in May 2007 and Headey filed for divorce five years later, in July 2012.