June 22 (UPI) — Marketa Vondrousova received a four-year ban for refusing to submit an anti-doping test, the International Tennis Integrity Agency announced Monday.

Vondrousova, the Wimbledon 2023 women’s singles champion, denied doping and said she has “never had a positive test” Monday on Instagram. She was issued a formal notice of disciplinary charge Feb. 27.

The No. 122 player in the WTA singles rankings said in April that she had a doping control incident, citing physical and mental stress. She also said someone rang her door “late at night without properly identifying themselves or follow protocol.”

ITIA officials said the Czech tennis star was notified about the test at her home about 8 p.m. Dec. 3.

“We understand that the testing process is uncomfortable, and acknowledge that it is an additional burden for players whose jobs already come with a high level of pressure and scrutiny, but it is essential to protect fair competition,” said Karen Moorhouse, CEO of the ITIA.

“Safety and welfare of players and our testers is really important to us. Our testers are well-trained, professional, and the gender of our testing witness always matches the player. They carry ID at all times, and players are able to verify their identity in other ways if they are ever unsure.”

The ITIA said Vondrousova presented explanations that “stress and poor mental health had affected her decision making, in additions to concerns for her safety.” An independent tribunal, which also heard testimony from the doping control officer who attempted to conduct the test, concluded that there was “no compelling justification” for Vondrousova’s refusal.

Vondrousova, the ITIA and Vondrousova’s national anti-doping organization have a right to appeal to decision to the Court of Arbitration for Sport.

Her ban expires June 21, 2030.

Vondrousova last played during a Round of 32 match against Russian Liudmila Samsonova on Jan. 12 at Adelaide International. She withdrew from her next match there, citing a hip injury. She also missed the Australian Open and the French Open, among other tournaments.