The company responsible for analysing bulk milk quality on hundreds of Welsh dairy farms says police are investigating a ransomware virus attack on its computer systems.

The attack has disabled services provided by the National Milk Records (NMR) Group for four weeks, including data reporting systems on milk payment testing.

NMR reported the attack to the National Cyber Crime Security Centre and police are involved in the investigation.

The company insisted there had been no data breach but the attack caused major disruption for its customers.

In a letter to farmers, NMR Group’s managing director Andy Warne dismissed speculation on the motive for the attack.

“The business community generally is suffering from an increasing number of this type of virus attack and we do not believe NMR was targeted by anti-dairy protesters.’’

A ransom demand has not been paid.

“NMR has engaged external consultants and have been advised that paying the ransom simply leads to increasing higher future demands,’’ said Mr Warne.

“Paying the ransom provides no guarantee of a solution to the problem in the longer term.’’

The company, through National Milk Laboratories (NML), holds the contract for milk quality sampling for many UK dairy processors. This information is used to calculate payments.

Instead of the usual data reporting system farmers received basic information via text messaging and email for four weeks before the systems were fully tested and restored on October 7.

Mr Warne apologised to customers for the disruption.

“I would like to thank all our customers for their continued patience as we work on the recovery of our systems and sincerely apologise for the disruption to the NMR Group services.

“The business is benefitting from the input of a number of external experts in back up restoration.’’

Mr Warne said the NMR group had engaged the services of a company to forensically examine its systems to establish how the virus managed to gain access, and to prevent future attacks.

He gave an assurance that laboratory testing procedures had not been affected and “remain as robust as normal’’.

Mr Warne admitted that the impact of the virus had been aggravated by its legacy IT systems.

These use older operating systems which are “challenging’’ to fully protect, he said.

“NMR has been in a process of investing and renewal of our legacy systems for some time.

“Unfortunately this attack has come before this upgrade process has finished.’’