The damage that led to the closure of Holyhead port for over a month between December and January was caused before Storm Darragh peaked, the port’s owners have said.

Giving evidence to a Senedd committee on Thursday, Ian Davies from Stena Line ports said the damage was caused by two ferries making “contact” with one of the berthing terminals.

The incidents happened on the 6 and 7 of December, before a red weather warning came into force.

The port partially reopened on 16 January and is due to reopen fully in July.

The incidents led to the closure of both berths at the port because of the “interconnecting nature” of the support structures – the terminals run parallel to each other.

In a written submission to the committee, ahead of Thursday’s hearing, Stena Line repeated that it was limited in the amount of information it could provide because it did not want to prejudice an ongoing insurance claim.

Stena explained the damage had happened to part of terminal three, which is “predominantly” used by Irish Ferries.

However, the firm has not said which company operated the vessels involved in the December incidents.

During Thursday’s hearing, committee chair Andrew RT Davies asked Stena Line boss Ian Davies if it would be “fair to say that it’s not necessarily the storm that’s caused this problem, because the storm wasn’t in full flow at the time – it’s more a case of the seamanship when the ships were docking and leaving the port that caused the damage?”

Ian Davies responded: “Correct. Correct, in the sense that this happened before that storm.”

Davies also told the committee that “contacts” between ferries and the berthing terminals happen “all the time” and that the terminals are “designed” to take “low-speed contact”.

Asked what was different in December, Davies said that was part of the “onward-going investigation” as well as an ongoing insurance claim.

In previous evidence to the Commons’ Welsh Affairs Committee Stena Line’s head of UK ports confirmed that there were “berthing incidents” on 6 and 7 December which rendered both ferry terminals inoperable.

Ian Davies went on to say: “Those incidents are now subject to an insurance claim and I can give no further details without prejudicing that insurance claims at this time I’m afraid.”

This was described as “very frustrating” by committee chair Ruth Jones.

The port was closed between 7 December and 16 January, with poor sea conditions delaying diving operations to inspect the damage caused to the terminal, according to the port’s owners.

Subsequent inspections were also delayed by sea conditions or visibility.

BBC Wales has been told that Irish Ferries were invited to attend the evidence session but did not respond to the initial invitation or a follow up.

Irish Ferries has been asked to comment.

Holyhead’s second berth T5 was reopened on 16 January, with both Stena Line and Irish Ferries now able to run a full schedule with the same number of sailings and capacity as previously.