Three matches contested at this year’s Wimbledon tournament will be investigated for possible match-fixing.

The Tennis Integrity Unit said it was alerted to three matches at the qualifying event at Roehampton and another from the main draw after unusual betting patterns.

It is believed the suspicious activity at Wimbledon this year was not related to the unusually high 10 mid-match retirements in the men’s tournament.

The Suspicious betting patterns have raised concerns that this year’s Wimbledon tournament may have been fixed, according to the Tennis Integrity Unit, the independent body charged with investigating corruption in the sport.

The watchdog group did not specify which matches had aroused concerns, but said that two took place during qualifying rounds, the earliest phase of the tournament, and that the third was during the main part of the competition.

The integrity unit received 83 alerts during the first half of 2017, down from 121 during the same period in 2016.