Peru has been informed by U.S. authorities that they were not planning to keep former Peru President Alejandro Toledo, who is wanted in connection with a corruption probe, from boarding a flight to Israel from California, a source in Peru's Interior Ministry said on Saturday.

Toledo was booked on a flight from San Francisco to Tel Aviv on Saturday, the source said, and is expected to land in Israel on Sunday evening.

The U.S. Justice and State Departments did not immediately respond to requests for comment.

The source, who spoke on condition of anonymity because he was not authorized to comment, said it was unclear why the United States did not want to detain Toledo. The government of Peruvian President Pedro Pablo Kuczynski was pressuring for the United States to change its mind, the source said.

The dispute threatens to strain relations between the United States and one of its traditional allies in South America.

Peru has an extradition treaty with the United States but does not have one with Israel.

A judge in Peru issued an international arrest warrant for Toledo Thursday, and the government offered a 100,000 soles ($30,000) reward for any information leading to his capture after he failed to turn himself in to authorities.

Peru has said Interpol issued a red alert to 190 member countries to help find him, but Toledo does not appear on its list of wanted persons. Interpol has not responded to requests for comment on Toledo.

Prosecutors in Peru allege Toledo took $20 million in bribes from Brazilian construction conglomerate Odebrecht and a judge ruled that he must be jailed for up to 18 months while charges against him are prepared.

Toledo, who has earned economics degrees from Stanford University, has denied wrongdoing and has not been charged or convicted of any crimes.

Toledo's lawyer said he did not know Toledo's whereabouts and declined further comment.

Toledo's wife has Israeli citizenship and Toledo has a long friendship with Israeli businessman Yossi Maiman, who prosecutors accuse of acting as a middleman for at least $10 million in alleged bribes.

A former Odebrecht executive has said he personally negotiated the bribes with Toledo in Rio de Janeiro in 2004, prosecutors say.

Maiman has not responded to requests for comment.

Kuczynski served as finance minister and then prime minister in Toledo's 2001-2006 government, when Peru awarded lucrative highway contracts to Odebrecht.