WASHINGTON (AFP) - Three Secret Service agents tasked with protecting US President Barack Obama during his visit to Amsterdam this week were sent home after a night of drinking, with one found passed out in a hotel hallway, a newspaper reported.

The three agents have been placed on administrative leave, the Washington Post said late Tuesday, quoting three unnamed people familiar with the case.

The embarrassing incident comes two years after an April 2012 scandal involving Secret Service agents and prostitutes in the Colombian Caribbean resort of Cartagena.

Then, a dozen agents and officers drank heavily and brought prostitutes to their hotel before the president's arrival for an economic summit.

Their activities came to light when one of the call girls had an argument in a hotel hallway after an agent refused to pay her. Colombia reported the incident to the US embassy in Bogota.

In the new case, the alleged behaviour would violate Secret Service rules adopted after the Cartagena scandal, the Post reported.

Secret Service spokesman Ed Donovan confirmed that the agency "did send three employees home for disciplinary reasons" and that they were put on administrative leave pending an investigation. Mr Donovan declined to comment further, the Post added. Reached by AFP, he also declined to give any details.

Mr Obama's visit to the Netherlands started with a brief stop at the Rijksmuseum, a fine-arts museum in Amsterdam, before he attended a nuclear security summit in The Hague and met fellow G7 leaders for talks on the Ukraine crisis.

Mr Obama flew to Brussels on Tuesday for his first ever visit to European Union headquarters, and is also due to visit Rome and the Vatican before heading to Saudi Arabia.

The Post said the three people sent home were members of the Secret Service's Counter Assault Team. That unit is tasked with protecting the president if he or his motorcade comes under attack and to fight off assailants and draw fire while the protective detail removes the president from the area.

The Post said the hotel staff alerted the US embassy in the Netherlands after finding the unconscious agent Sunday morning, a day before Mr Obama arrived in the country, according to two of the people it quoted.

The embassy then alerted Secret Service managers on the presidential trip, which included the agency's director, Julia Pierson.

Under the new post-Colombia rules, staff on an official trip are banned from drinking alcohol in the 10 hours leading up to an assignment.