Lady Gaga. Picture: Supplied/Bang Showbiz

Lady Gaga has been subpoenaed to testify in Dr Luke's ongoing legal battle with Kesha.

The music producer is keen for the star to hand over evidence such as text messages sent between her and Kesha in which the 'Tik Tok' singer stated she was abused by Luke and claimed there was another victim.

The producer's legal team said in a statement obtained by PEOPLE: "In connection with Dr. Luke's defamation claims against Kesha, various third parties are being deposed by both sides, including celebrities.

"Dr. Luke's counsel served a subpoena on Lady Gaga because she has relevant information regarding, among other things, false statements about Dr. Luke made to her by Kesha. This motion has become necessary because Dr. Luke's counsel has not been able to obtain, despite repeated request, a deposition date from Lady Gaga."

In 2014, Kesha, 30, accused Dr. Luke of sexually abusing her, drugging her, and emotionally abusing her for years but he has denied the claims.

And the statement goes onto say Gaga, 33, was allegedly encouraged to embark on a "smear campaign" against the 43-year-old producer.

However, she has hit back at Dr Luke and insisted he has exaggerated her role in the case to gain press attention and that her evidence is merely providing necessary support to get to the truth. 

A statement from Lady Gaga's representative to PEOPLE said: "As Lady Gaga's legal team will present to the court, she has provided all of the relevant information in her possession and is at most an ancillary witness in this process. Dr. Luke's team is attempting to manipulate the truth and draw press attention to their case by exaggerating Lady Gaga's role and falsely accusing her of dodging reasonable requests."

She recently submitted a number of emails to court in which the music producer slammed her weight and was critical of her appearance.

Dr Luke - whose real name is Lukasz Gottwald - reportedly wants to add a defamation charge to his own lawsuit against Kesha over the text messages to Lady Gaga.