Unfortunately its not good news, this is a failure within the LCD panel (the panel itself can not be repaired), which means replacement, this is the most expensive part of the TV set, to this end its likely to be uneconomical to repair.
The issue is caused when the internal electronics within the LCD lose connectivity to one of the many 1000s of lines which make on the LCD panel, each line is made up of three colours (Red, Green and Blue), in this case the fault is making the LCD screen believe RED should be displayed, and hence why you getting a straight red line across the display.
If you provide me with your postcode I can certainly recommend a suitable repair centre who can give you a quote for replacing the LCD panel, or failing that recommend an equivalent model if your looking to buy new, I just need to know your budget.
I just wanted to follow up and check if you required any further assistance, and request you rate the service received so I may resolve this case.
I havent heard from you in a few days, and I just wanted to follow up and check if you required any further assistance?