Google has responded to the criticism received after it was revealed its 'DeepMind' data-sharing deal with the UK National Health Service (NHS) was more widespread than previously disclosed – containing data on 1.6 million hospital patients going back five years.

Speaking out against claims that the project will be an invasion of privacy, the co-founder of the project, Mustafa Suleyman, told The Guardian: "As Googlers, we have the very best privacy and secure infrastructure for managing the most sensitive data in the world. That's something we're able to draw upon as we're such a core part of Google."

As previously reported, Google's DeepMind – which traditionally consists of artificial intelligence projects – signed a deal with London's NHS Royal Free hospital and will use sensitive medical data to boltser future research.

According to documents exposed by The New Scientist, the datasets will contain information on people who are HIV-positive and patients who have gone through abortions and drug overdoses.

Google first announced it was working with the NHS back in February however at the time only disclosed an application called 'Streams' that aims to help hospital staff monitor patients with kidney disease.

In light of the expanded reach of the data, the reaction from privacy groups was swift. Sam Smith, director of campaign group MedConfidential, said: "This is not just about kidney function. They're getting the full data."

However, in response to mounting controversy – and media coverage in the UK – Suleyman is now seeking to reassure critics that any data included in the project will be kept secure. He said: "When we developed our information governance toolkit and we submitted that for assessment to the health and social care information centre, which approves these data-sharing agreements, we got 100% for our toolkit. There's pretty much nobody else who's been able to get a score as high as that."

In the fine print, the agreement states that Google is not allowed to use the data in any other section of its global business – which largely relies on advertising and personal data to function. Meanwhile, according to The New Scientist, the data will not be stored by Google itself but instead by a contracted third-party in the UK. Furthermore, DeepMind will be 'obliged' to delete its copy of the data when the sharing agreement expires in September 2017.