3 August 2012 Last updated at 16:44 ET

Hundreds of Games tickets on sale illegally

By Jane Bradley Investigations producer, BBC London

Hundreds of tickets for Saturday's Olympic events are illegally on sale at a major ticket agency in the capital, BBC London has learned.

Many tickets came from allocations given to the National Olympic Committees (NOCs) of European countries,

These should be returned to the Games organisers if unsold.

It appears they have been illegally passed to a ticket tout who is trying to sell them to the public at a profit.

'Urgent investigation needed'

London Olympic organisers say they will investigate immediately if there is any evidence of rules being broken.

2012 tickets are only allowed to be sold by authorised ticket resellers and NOCs.

But the BBC has seen several hundred Olympic tickets for Saturday's events including swimming, volleyball, and boxing being touted by an unauthorised ticket broker.

The face value prices ranged from £20 to £185.

A BBC journalist contacted a tout to ask if Games tickets were widely available on the black market.

He agreed to show how many tickets from authorised ticket sellers are ending up on the black market on the conditon he remained anonymous.

The tickets filmed by BBC London had the names of different countries' NOCs on them. It is unclear whether they came directly from NOCs or from members of the public.

The ticket broker said he would often pay double the face value for tickets to popular events and would sell them on for a "small profit" to customers.

Shadow Olympics Minister Tessa Jowell said: "People will be rightly angry when they hear about this and people will rightly want to see the perpetrators of what appears to be a crime, punished."

A Locog spokeswoman said: "We have made it very clear to all NOCs and their Authorised Ticket Resellers that selling tickets through sources other than those authorised by us is illegal.

"We expect the rules to be followed and the IOC and Locog will investigate immediately if there is evidence that rules have been broken."