This is despite British tennis' governing body getting a £7.2m increase in revenue from Wimbledon in 2018.

BBC Sport reported in November how the loss for 2018 could be as high as £7.5m - a figure the LTA described at the time as "wildly inaccurate".

The latest figure follows losses of £3.6 and £1m in the previous two years, and a profit of £1.2m in 2015.

The LTA does, though, have vast reserves, and will receive 90% of the surplus from Wimbledon until 2053.

Commercial revenue fell by just over £4m in 2018, primarily because the LTA's extremely lucrative nine-year partnership with the financial services company Aegon ended the previous year.

Operating expenditure increased by £2.6m, with "exceptional expenditure" of £1.9m down to an internal reorganisation.

The LTA also suffered a net loss of £3.6m on its investment portfolio but still has total equity of £161.4m.

An LTA spokesman said: "At the end of 2018, the market value of investments fell and this loss increased the loss for the year by £3.6m, which we weren't aware of in early November when the BBC approached us.

"Secondly, the LTA has committed reserves to a capital investment programme into building and improving Britain's tennis infrastructure, such as building new indoor courts in areas where there isn't any tennis provision currently.

"Finally, we planned for an operating loss in 2017 and 2018, but we took the decision not to decrease spend on performance and participation despite this temporary drop in income."

A third of the LTA's expenditure goes into staging tournaments, primarily in the run-up to Wimbledon.

Just over a quarter is invested in increasing participation, and 14% is directed towards the performance budget.

The chief executive Scott Lloyd conducted a "listening exercise" when he joined the organisation in January 2018.

Last June, the LTA launched a 10-year performance plan, and then in March unveiled a new logo and a strategy "to open tennis to as many people as possible, across the whole of Britain".