The hack of Jaguar Land Rover, owned by India's Tata Motors, cost the British economy an estimated 1.9 billion pounds ($2.55 billion) and affected over 5,000 organisations, an independent cybersecurity body said in a report published on Wednesday.

The report was produced by the Cyber Monitoring Centre, an independent, not for profit organisation made up of industry specialists, including the former head of Britain's National Cyber Security Centre. It said losses could be higher if there were unexpected delays to the restoration of production at the vehicle manufacturer to levels before the hack took place in August.

"This incident appears to be the most economically damaging cyber event to hit the UK, with the vast majority of the financial impact being due to the loss of manufacturing output at JLR and its suppliers," the report said.

JLR will report its financial results in November, according to the company's website. A spokesperson for JLR declined to comment on the report. The company started to resume manufacturing earlier this month after an almost six-week shutdown caused by the hack. The luxury carmaker has three factories in Britain that together produce about 1,000 cars per day. The incident was one of several high-profile hacks to affect major British companies this year. Retailer Marks & Spencer lost about 300 million pounds (about $400 million) after a breach in April shut down its online services for two months.

JLR, which analysts estimated was losing around 50 million pounds per week from the shutdown, was provided with a 1.5 billion pound loan guarantee by the British government in late September to help it support suppliers.

The CMC, which is funded by the insurance industry and categorises the financial impact of major cybersecurity incidents affecting British businesses, ranked the JLR hack as a Category 3 systemic event, out of a scale of five.

The CMC's estimate "reflects the substantial disruption to JLR's manufacturing, to its multi-tier manufacturing supply chain, and to downstream organisations including dealerships," the report said.