Under Fifa regulations Essien was ineligible for the game because he refused to turn up for Ghana’s friendly in Angola the previous Wednesday. At the time, the Ghana FA said they would take action against Essien and absent teammates Sulley Muntari and Asamoah Gyan.

All three apologised and each was fined £3,000. Wenger believes Essien should have been suspended for Chelsea’s subsequent Premier League fixture, the 3-0 win at Arsenal. ‘Essien didn’t play for Ghana but he still played against us,’ said Wenger.

‘He was not entitled to do so.’ As the story gained impetus last night, Wenger said: ‘We will investigate to see if there has been a breach of the regulations.’ Chelsea say the matter is a ‘non-issue’ because they have written permission from Ghana’s FA to use Essien.

There are doubts, however, about the value of that letter: Muntari’s club, Inter, also received a communication from Ghana’s FA, but were told by the Italian federation that it made no difference and Muntari was left out of the Inter squad to face Bologna. Fred Pappoe, the Ghana association’s vice-president, told The Sunday Times he was unaware any permission had been granted.