An inquiry into the death of Dinamo Bucharest midfielder Patrick Ekeng has revealed the ambulance company that took him to hospital had faulty equipment and medicine beyond its expiry date in some of its vehicles, Romania’s interior ministry said.

The Cameroon international collapsed on the pitch from a suspected heart attack shortly after coming on as a 62nd-minute substitute in a match against Viitorul Constanta on Friday. He was pronounced dead two hours after the incident.

After Ekeng’s death, world football’s players’ union, FIFPro, raised concerns about the level of first-aid treatment for footballers in Romania, saying: “It is clear that some Romanian clubs have a history of skimping on medical facilities.”

The interior ministry said it had suspended the licence of private company Puls for at least 30 days and imposed fines totalling 23,800 Leu (£4,185) following an investigation of its equipment and the professional qualifications of its staff.

The ministry said in a statement issued late on Sunday that the investigation had revealed defibrillators with expired batteries in some ambulances belonging to the company, and medicine used in resuscitation procedures that had expired.

The results of an autopsy – in which a Cameroon doctor also took part – are expected to be published later on Monday Ekeng’s agent also criticised the treatment received by the 26-year-old. “The ambulance arrived late,” said Hasan Anil Eken. “Actually there were three ambulances around the stadium but none of them had a defibrillator.”

Prosecutors in Bucharest announced on Saturday they had opened an enquiry into Ekeng’s death amid criticism of the treatment he received.