Detectives used CSI-style DNA testing to track down a couple from Shropshire who ran off from an Aberystwyth bed and breakfast without paying the £130 bill.

Mother-of-one Sasha Rocke, 20, and her boyfriend Matthew Clinton, 26, from Caradoc View, in Hanwood, failed to pay for their stay at Helmsman Guest House in Aberystwyth after a benefits cheque did not appear in their bank account.

Specialists were called in to the seaside bed and breakfast to take a DNA profile of hair, skin and fibres from an overnight bag.

A swab from the luggage matched a profile that police had of Rocke and detectives were able to track down the couple to their home 75 miles away in Hanwood, near Shrewsbury.

Rocke and Clinton both pleaded guilty to theft in their absence at Aberystwyth Magistrates’ Court on November 23 and were ordered to pay back the three-star guest house as well as £85 in costs.

Dyfed Powys Police confirmed that the cost of the DNA profiling was more than the cost of the hotel bill, but would not give a figure.

A spokesman for the force said that the technique was a valuable crime-fighting tool to track down petty criminals as well as catch the more serious offenders.

She said: “Police will use all available scientific means, including DNA testing, to support investigations and to identify offenders.”

Consultant forensic scientist Nigel Hodge said after the case: “These crimes do happen – unfortunately people occasionally do runners.

“Talk to anyone who works in a petrol station and they’ll tell you that people sometimes fill up and drive off.

“Cost is an issue. Is it worth spending all that money for a crime which perhaps involved the theft of £50? But police also have to take into consideration their obligation to investigate offences, and the impact of crimes on victims. DNA profiling has also been shown to act as a deterrent.”

“Perhaps we have to let people know they cannot get away with these things.”

No-one was available to comment at the guest house.