Plans for a £600m (US$972m, €771.4m) aquarium in Bedfordshire, UK, have fallen through after planning permission for the project expired despite millions of pounds worth of public investment.

The National Institute for Research into Aquatic Habitats (Nirah) initially gained approval to be built in Stewartby in 2007 and the collapse of the plans has left the Bedford Borough and Central Beds councils owed at least £1.6m (US$2.6m, €2m), with the government owed more than £3.5m (US$5.6m, €4.5m) by the developers.

The aquarium was originally presented as a scientific research centre and visitor attraction, and was supposed to be built by the end of 2012 but lack of investment meant work on the project hasn’t been able to proceed as planned.

The government originally loaned the aquarium £2m, but due to interest its at the figure standing at £3.5m.

The government warned in March that it wanted to see "evidence of progress" on the giant aquarium project, with the Department for Business, Innovation and Skills calling the situation "not sustainable".

The government and councils, are currently seeking to recover the debt, much of which is secured against the value of the land.

Nirah is yet to comment.