Passengers sat with their hoods up as water poured through the roof of a rush-hour train, it has been claimed.
Maz Brooks took photographs of the leaks, on the 5pm Sheringham to Norwich train at North Walsham, and shared them - showing water covering the tables.
Mrs Brooks said: "We were on the 5pm train from Sheringham to Norwich having to sit with our hoods up as the roof was leaking all the way through and the train seats were soaked. Can this service get any worse?"
A Greater Anglia spokesperson said: "We'd like to apologise to customers on yesterday evening's 16.47 Sheringham-Norwich service.
"Our engineers had identified leaks in the roof of the train and fixed them, however it appears that during heavy rain, the roof began to leak again in places. We're very sorry for the discomfort this caused customers.
"We will fix the leaks again as we are working hard to keep our existing old trains in good working order while at the same time we're rolling out new trains. The Sheringham line is the next route to get new trains later this autumn."
This incident comes two weeks after this newspaper reported rain water pouring into an old Greater Anglia train.
Water was pouring between two of the carriages on the 4.45pm train between Norwich and Sheringham on Friday, September 6.
The leak caused large puddles not just in between the trains but also on the carpet in the aisles.
A passenger on the train said: "Water was pouring through the roof in between the two carriages. It was forming a puddle on the floor and absolutely soaking the carpets.
"Some people were having to stand in the section between the two carriages as the train was busy, so they might have been getting wet too."
Over the past few months passengers travelling on the Bittern Line trains have had problems with overcrowding.
On July 22, passengers' told of their frustrations at overcrowding on the line, with one July 19 service reportedly having "hundreds" of people aboard one carriage. These were branded "unacceptable" by MP Sir Norman Lamb.
Following the reports of single carriage trains on the Bittern Line, the North Norfolk Lib Dem demanded an explanation from the rail firm.
Sir Norman said in a letter to Greater Anglia: "The reports of overcrowded service on the Norwich to North Walsham line are incredibly frustrating.
"I'm sure this sentiment is shared by the commuters on the line who are having to endure standing room only conditions too frequently. In the current hot weather, having to stand in an overcrowded train can be incredibly unpleasant."
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