Is a leaseholder liable for water damage to flats below?

I am a leaseholder of a top flat of a multi-storey building. A water leak occurred on the flats underneath mine on Sunday, 13/7/2025. The fire brigade was called, and according to my tenant, they advised to keep an eye out for any leaks, as they did not know the source.

The fire brigade was called again, and they had to forcibly open the fire door of the flat under mine, as not occupied. The fire brigade told my tenant that the leak is from our flat.

On the same day, I contacted the plumber who did the work around 3 months ago. Everything was done as new at the time. He investigated and fixed the leak from the bath overflow

On Tuesday, 15/7/25, I received emails from the property management company that the leak is continuing. I hired another plumber who attended on 20/7/25 and redone everything and fixed the source of the leak

The property management company appointed a contractor, and I met them on 29/7/25 when they inspected the work, and they were satisfied with the remedial actions taken.

On 24/7/25, I received an email from the property management company advising me that they appointed a contractor to investigate the root cause of the leak and the extent of the resulting damage (this included the 2 flats underneath mine).

An insurance claim has been opened and they gave me the reference number. They asked me to send invoices for the work I did to sort out the leak from my flat.

However, the leaseholder of the flat immediately under mine continues to send me text messages asking to pay him for damages and loss of income.

He has continually messaged to say he will take me to court.

On 09/01/26, I received an email from the property management company forwarding a message from him, requesting payment for damages and loss of income.

On 23/7/25, I offered him £400 out of courtesy, which he refused and said he is starting legal proceedings next week.

Any advice on how to handle this situation would be greatly appreciated.

Thanks,

Anonymous