LONDON – International Olympic officials have opened a high-level investigation into allegations that authorized representatives in more than 50 countries — including a national Olympic committee — were involved in selling London Olympics tickets on the black market for profit.

The International Olympic Committee convened an emergency session Saturday to discuss a dossier of evidence presented to it by Britain’s Sunday Times. The newspaper published an investigation Sunday claiming that officials have been offering tickets for the July 27-Aug. 12 London games, including highly sought-after events such as the men’s 100-meter final, at vastly inflated prices.

One of the most damaging allegations was against Spyros Capralos, the Greek Olympic Committee president and top organizer for the 2004 Athens Olympics.

He was quoted as saying he had “pulled strings” with London organizing chairman Sebastian Coe to obtain an extra batch of premium tickets for official agents in Greece, on the pretext that demand in his country had outstripped expectations.

The paper said Capralos acknowledged in talks with its undercover reporters that demand had actually been very low and that many of the tickets were subsequently sold to people outside Greece for profit.

The London organizing committee said Capralos’ alleged boasts of discussions with Coe were untrue. Coe had told the Greek Olympic Committee that tickets were allocated in accordance with IOC ticketing policies, it said.

At issue are ticket allocations given to each of the 205 national Olympic committees to sell in their home countries. The committees appoint an organization within their countries to sell the tickets, a process meant to ensure equity.

IOC rules forbid national committees from selling tickets abroad, inflating ticket prices or selling tickets to unauthorized resellers.