Three Centre Court tickets were bought by Spanish tourists for pounds 750 from a man calling himself John at a cafe in Southfields near the All England Club.
He said they were American players' tickets and advised the tourists on how to answer questions if challenged.
The Spaniards handed over $1,200 (pounds 750) after they were told to go to Gate 2, pay a normal pounds 7 entry fee to the grounds and then go to Centre Court seats with the tickets.
A spokeswoman for Wimbledon said that, at this stage, without the relevant reference numbers, it was impossible to check if the tickets had come from players.
The inquiry comes as touts increasingly target foreign visitors to the championships following the success of the club's drive to educate the public about buying invalid tickets.
Players face a severe reprimand if found to be directly responsible for putting tickets on the black market.
Touts have previously kept a relatively low profile this year. Police have had a specialist squad in action again stepping in to prevent sales and plain clothes officers are carrying cameras to take instant snaps of suspects.
However, groups of touts - many of whom are familiar faces after years of doing business on the streets between Southfields and the club - were gathering again today.
It is usually the last few days of the tournament when the semi-finals start that the big money is made. All Wimbledon tickets, except debentures, are non-transferable.
But foreigners, who often turn up for the tournament with large amounts of cash on the off-chance of getting in, are easy prey for the touts.
The success this year of Japanese players Shuzo Matsuoka and Kimiko Date, who both reached the quarter-finals, reportedly boosted the touts' profits after Japanese fans paid hundreds of pounds for tickets.
Last year, a German businessman paid more than pounds 50,000 for 35 Centre Court tickets to entertain some of his most valued customers - but all were invalid and the group were not admitted.