Details of attacks on contractors installing meters on behalf of Irish Water, including physical assaults, have been sent by the company to Dublin City Council.

The council wrote to managing director of Irish Water John Tierney in October to raise concern about what it described as “excessive mobilisation of gardaí” during meter installations.

The letter followed the adoption of a motion by councillors supporting “peaceful resistance to water meter installation” and condemning the arrest and forcible removal of protesters by gardaí and the mobilisation of the Garda public order unit in housing estates in north Dublin.

In response to the letter, the company has detailed attacks it says have been made on meter installers and their property.

Workers have been punched and headbutted, the letter said.

“They have received death threats and threatsreasonably possible, while maintaining the safety of the staff, the public and the site of work,” it said.

The letter is signed by Fergus Collins, head of capital delivery with Irish Water, rather than by former city manager Mr Tierney.

Separately, gardaí are continuing to investigate the circumstances surrounding a letter containing excrement which was posted to a call centre contracted to deal with Irish Water queries last week.

The Cork-based company Abtran, which employs 1,500 people, confirmed that “offensive material” had been received and Garda have been informed.

The incident is an isolated one, according to Abtran, which has assigned some 400 staff to deal with the Irish Water brief.

Last week a 59-year-old man was arrested in Clarecastle, Co Clare, following reports he had threatened water meter installers with a rifle.

He