The Tennis Integrity Unit has confirmed three matches from this year's grand slam, including one from the main draw, are currently under investigation for potential match-fixing violations.

Alerts were triggered on two matches at the qualifying event at Roehampton and one from the main draw on court at Wimbledon after some unusual patterns.

TIU stress an alert is not evidence of match-fixing but the matches will be reviewed in accordance with their policy.

It is rare for Wimbledon to be flagged as generally alerts come from lower levels which are under less surveillance and the players are earning less income.

Last year Buzzfeed News and BBC released a joint investigation report which alleged wide-spread match-fixing at tennis's highest levels.

Since the report, the TIU has doubled their staff to investigate more alerts.