Jess Phillips, minister for safeguarding and violence against women and girls, said the BBC's findings "appalled" her, but added she was not surprised.
Speaking to Radio 5 Live, she said some of the reasons for the delays were "completely legitimate", such as when court cases were ongoing, but added the system could be "a bit clunky".
The Home Office was working to recruit more chairs and to make sure they go through mandatory training, she said.
Phillips accepted more needed to be done to ensure the process was "effective and timely", but doing them faster was not the answer to saving lives.
"Doing them really well and really thoroughly… is actually more important to me than the time," she added.
She said a new oversight board with publicly appointed members is set to make the process of reviewing reports faster.
A Home Office consultation last year suggested increasing the timeframe to complete a review from six to 12 months – but no change has yet been made.
Even with the extension, BBC analysis suggests most would still miss the deadline – only 18% of the reviews were completed within one year.
Frank Mullane campaigned for domestic homicide reviews to be introduced after his sister Julia Pemberton and nephew William were murdered by Julia's estranged husband in Berkshire in 2003.
Mr Mullane, who set up charity Advocacy After Fatal Domestic Abuse to help other families, admits he is "hugely disappointed and somewhat angry" to hear about the slow progress other grieving relatives have experienced.
However, he praises the impact of domestic homicide reviews.
"Now we have evidence and detail of what it is like to live a life of domestic abuse, which then culminates in either homicide or suicide," he says.
"This is detail that never existed before."
