UK officials are considering banning the sale of small mobile phones designed to resemble car key fobs.
A government spokesman told the BBC that it was discussing the issue with the National Trading Standards Board and the Serious Organised Crime Agency.
In the meantime the NTSB has asked retailers to stop selling the products
The Times had reported some of the Chinese-made products were being advertised with prisoners in mind - having a mobile in jail is an offence.
The devices, in some cases marketed as the "world's smallest mobiles", are available from mainstream retail websites including eBay and Amazon.
They are designed to resemble the fobs used to transmit a signal to unlock vehicle doors, and feature logos from brands including BMW, Volkswagen, Bentley, Audi and Porsche.
A spokesman for the UK's Society of Motor Manufacturers and Traders said it believed the devices were being made without its members' permission.
The product description of one device sold via Amazon states that it features "very very very low metal contact badges [which] can be removed due to metal content alarm", while another says the fob is "easily concealable".
The Times said it had spotted one advertised elsewhere alongside a cartoon of a prisoner behind bars.
A prison service spokesman said it was already making efforts to detect the devices.
"A range of techniques - including body orifice security scanners and high-sensitivity metal detectors - has seen the [overall] number of recorded seizures increase," he said.
"We're now working closely with the Serious Organised Crime Agency and Trading Standards to remove these small mobiles from sale in the UK, as well as legislating to block phone signals in prisons."
More than 7,000 phones and Sim cards were confiscated in prisons in England and Wales last year.
The POA - a prison officers' trade union - confirmed its members were also concerned the gadgets could make things worse.
"The latest key fob mobile phone has the potential to increase the number of mobiles in prisons simply by the nature of the design and size.
"This will lead to further problems in prisons and whilst we recognise the work of the Ministry of Justice and the National Offender Management Service in addressing this issue, more needs to be done.
"The POA believe all prisons should have blockers installed and prisoners found in possession of a mobile phone should be prosecuted."
A spokesman from Soca said the police unit had asked car makers to take a stand over the issue.
"By issuing alerts that warn of criminal dangers and threats, Soca seeks to arm specific organisations and sectors with information and advice they can use to protect themselves and the public," explained a spokesman.
"In this case Soca assisted the prison service and the National Trading Standards e-Crime Centre by issuing an alert to car manufacturers and online retailers earlier this year to make them aware of the issue so they can consider taking copyright infringement action against those selling these phones."
The Society of Motor Manufacturers and Traders told the BBC it planned to co-operate with the authorities.
"We are aware of the existence of these mini-mobile phones and that a number of them bear resemblance to car keys bearing manufacturer logos," said a spokesman.
"We agree that these devices are potentially damaging and will work with Soca on this matter."
The NTSB e-crime centre said it was urging online retailers to stop selling the fobs, and members of the public not to buy them.
"There is a strong possibility that these products were not put through the stringent safety testing UK products go through, which means that there is a chance they are electrically unsafe meaning they could cause fires and injure consumers through electrocution," it said.
Amazon and eBay were unable to provide comment when asked.