This follows allegations made by Buzzfeed News and BBC News claiming that 16 players have been repeatedly highlighted as having potentially thrown matches, with concerns reported to the Tennis Integrity Unit (TIU).

All 16 of the unnamed players have been ranked in the top 50 in the world across the past decade, it was claimed.

All have been allowed to continue competing, despite several of their matches being deemed suspicious, with Italians Potito Starace and Daniele Bracciali the only professionals to have been investigated and charged.

The duo are due to appear in court in May and both deny charges of conspiracy to commit sporting fraud.

Cramona-based prosectutor Di Martino believes tennis authorities should be doing more.

But the TIU "strongly refutes" any suggestion that evidence of match fixing in tennis has been ignored. 

All information received from the Public Prosecutor is being "fully and thoroughly assessed, verified and, where appropriate, investigated under the powers of the Tennis Anti-Corruption Programme," a statement added.

He claims more than 24 non-Italian players had been mentioned by gamblers in recordings of phone calls and internet chat logs.

"Surely if these foreign players were Italian, they would certainly have been at least questioned," he told the BBC's File on 4 programme, opting not to reveal any of their identities. 

"They should have provided some explanations.

"Interestingly, they are not so-called second-tier tennis players, but also players of some importance."

He criticised the TIU for allegedly failing to act on hundreds of alerts it has received about suspicious betting on tennis matches.

"I do not understand why there was no real initiative by the integrity unit to establish if there was something dirty behind this," he added.