Sinn Féin leader Mary Lou McDonald has said that the party has appointed a data protection officer following correspondence with a State watchdog over past week.

In an interview with RTÉ's Prime Time, she said: "We had a data compliance officer in the party we now have appointed a data protection officer."

Her comments come following continuing political controversy over the party's handling of a database with details of voters.

Ms McDonald said the appointment was made on foot of initial correspondence with the State's Data Protection Commissioner (DPC).

She said the DPC had been in contact with the party following "media stories" about the database.

Ms McDonald said the appointment was being made out of "an abundance of caution" and in terms "good practice in terms of risk assessment".

In the interview, she said the party was fully compliant with legislation, but she added the appointment "is by way of meeting what was a gap in the compliance identified".

Earlier, Ms McDonald said that the party's voter database, known as Abú, is held on servers in Germany.

During an interview with Newstalk, Ms McDonald said that Abú contains the "returns from canvases" and that the information is stored in Frankfurt.

She explained that the server was located in London, but after Brexit its location had to change. She said that the database is "legally stored" in the European Union.

Ms McDonald said that Abú is an old fashioned "canvassing system" that is no longer compiled with a pen and paper, but rather held electronically.

She said that she felt "a spin" had been put on the story to "hype it up" and insisted that the "canvass material" is used for electoral purposes.

The Data Protection Commission wrote to Sinn Féin last week to seek more information about the Abú system.

Ms McDonald said that the party had replied to all questions from the DPC, which included providing an explanation of the legal basis for the processing of the information contained in the database.

Asked why the information could not be stored in Ireland, Ms McDonald said that such a query was a "technical question", adding that it "doesn't really matter which jurisdiction it is held in, as long as it's held in the European Union".

"There's nothing nefarious, there's nothing untoward here," she told the station.

Asked if Abú was used to identify potential Sinn Féin voters and if such practice crossed a line, Ms McDonald replied "that would not be crossing the line", adding that "every political party, every political candidate uses the electoral register to know who is registered to vote and then to come and canvass your vote and then to establish, in their judgement, the likelihood or otherwise of you voting for them".

Ms McDonald said the Electoral Register is a "very public document" that is available to all politicians.

She said it is used to "forward plan" for elections, and that she believes many other politicians used the register for a similar purpose.

Sinn Féin's housing spokesperson Eoin Ó Broin said the party is fully compliant with the law in keeping its online database of voters in a server in Frankfurt.

He said the party has chosen to use a provider in Germany because it satisfies the stringent security requirements, and because the law requires the data to be held in the EU.

He said he did not know when the database was moved from the UK to Germany. Asked if the individuals whose data was held on the file were informed that it was being moved, he said there is no legal requirement - to the best of his knowledge - to inform them.

The Data Protection Act 2018 gives political parties and party candidates access to the register and allows them to use the Electoral Register in the way Sinn Féin "and almost every other political party uses it," he said.

"So we are not doing anything that is not consistent with the law."

On Monday, Mr Ó Broin told journalists it was "not true" that his party was "data-mining from Facebook".

He said any information gathered from the platform is done so consensually, and insisted that it is not uploaded to the party database.

Additional reporting Tommy Meskill, Mary Regan