A watchdog has called for more people to visit a free Olympic live site at Victoria Park saying only a quarter of the number of visitors expected have turned out.

Despite musical events, alongside live sport, visitors are failing to show up, according to the Commission for a Sustainable London 2012, which believes people may be deterred by not being allowed to take in food and drink.

The independent watchdog said Victoria Park is “well under” its capacity to hold 20,000 people at any time. It is one of two BT London Live venues, the other is Hyde Park.

Attendances have been averaging at 8-10,000 per day, with up to 15-16,000 at the weekend, according to its organisers.

The Commission’s chair Shaun McCarthy said: “The Live sites are a wonderful contribution to making the Olympics accessible to all.

“It is shocking to learn crowds are way below expectations. My message is, come on London. Let’s get this party started.”

In a statement the commission is calling for food restrictions to be relaxed to try to attract more visitors.

The commission also believes people are failing to turn up because they wrongly think events are fully booked.

A spokeswoman for BT London Live said: “Working in close co-operation with the Olympic Security Directorate we’ve had to put in place strict airport style security measures to ensure safety of visitors.

“These regulations are broadly similar to regulations at the Olympic Park. We’ve relaxed rules regarding children’s sweets. Those with special requirements, including dietary, religious needs, or baby requirements, have never been restricted from bringing foodstuff.”

“Victoria Park offered a number of guaranteed entry tickets per day, which included 4,000 tickets ring-fenced for Tower Hamlets residents.

“These tickets are only valid until 2pm each day and were designed to ensure visitor numbers were spread evenly over the day. Whilst some days are sold out, such as for the closing ceremony, there’s still lots of spare capacity for people wishing to turn up on the day.”

Chair of the Victoria Park Friends Group, Richard Desmond, declined to comment on people not being allowed to take food and drinks into the park.

But said: “We don’t have a policy on it. But the park is empty, so that speaks for itself.”