Ajla Tomljanovic has described the lengthy doping ban administered to Marketa Vondrousova, the 2023 Wimbledon singles champion, as a disgrace and she has accused the tennis anti-doping authorities of being out to get players even when they have done nothing wrong.

The International Tennis Integrity Agency announced on Monday that Vondrousova had been handed a four-year suspension by an independent tribunal after the Czech player had refused to provide a sample to a doping control officer at her home last December at around 8pm.

“I wouldn’t be comfortable if I’m living alone and someone comes at 8 or whenever,” Tomljanovic said. “Overall, I can count on one hand good experiences with these people. I think they’re always out to get you. They’re not very nice.

“It’s kind of a disgrace what’s happened to Marketa. It’s really sad that we’re part of a sport where I think that if you’re ... like the treatment isn’t equal. Equality is what we strive for. It’s just insane.

“I hope she appeals. I hope it gets better, but it’s never good when the first ruling is a four-year ban. I just think that the whole ITIA, they’re so cocky. They’re almost out to get you even if you are doing nothing wrong.”

Tomljanovic, a veteran Australian tennis player who twice reached the quarter-finals of Wimbledon and famously ended Serena Williams’s first career in 2022, learned of Vondrousova’s verdict after winning her first match in Eastbourne on Monday. “I saw that after my match and I was just so angry. She doesn’t deserve that. And it’s never really going to change because these people ... I’ve spoken to a guy that’s in a position of power – you can see that he just hates almost ... He just wants to get anyone for anything. It’s awful.”

According to the ITIA, after being reached at her home by a doping control officer at around 8pm last December, Vondrousova signed a release form to signify that she was refusing to provide a sample to the female doping control officer and she was therefore aware that this decision would have consequences. Vondrousova, who had initially said that she had been scared by the presence of a stranger outside her home, signed the form outside her home and then took her dog for a walk. “It was very clear that the player did not wish to engage with the process,” said Nicole Sapstead, the ITIA’s senior director of anti-doping.

During the tribunal, Vondrousova said she had been suffering from acute stress reaction and generalised anxiety disorder, which impaired her decision making. The independent tribunal found “no compelling justification” for her to have refused a test.

Vondrousova has received support from some of her fellow players since the verdict was announced. Fran Jones said: “I have a lot of empathy for Marketa. I think a four-year ban is extreme for someone that’s never had a negative test. And I really feel for the girl. She’s a really good person. I just have goosebumps saying it. I can’t imagine how she feels today.”

However, there have been differing opinions on her case. In an interview with the Guardian in April, before the case had been heard, the former world No 1 Karolina Pliskova seemed unconvinced by her compatriot’s arguments. Pliskova said: “I’ve been on tour for maybe 15-20 years, so I think everybody experiences this kind of situation where they just knock on your door, but we all know the rules, so …

“For me, this is quite clear. Maybe for somebody [else] not. I know she’s maybe a bit younger, maybe she wasn’t in the mood. I don’t want to say too much because I already said it in [my] podcast and it didn’t go [down] well. But for me, this would never be an option not to give the test.”

In a statement, an ITIA spokesperson said: “This case – unfortunate as it is for the individual – should make it clear that players can and will be tested outside of their allocated hour. Everyone wants a clean sport and to achieve this we need to have a strong testing programme which must be unpredictable.

“We know this can be challenging for players. Having someone in your home or hotel room to watch you pee is stressful. We believe most of our testers deal with this in a respectful way, but they too have a challenging and not always pleasant job. We would encourage any player who has questions about the process, or issues with a tester to talk to us. We will always listen to any concerns or feedback.”