The mother of a university student who died in a suspected suicide in March has also died suddenly.

Monica Soni died by suspected suicide last Wednesday. She had been battling the coronial system for the release of two letters written by daughter Niki Soni hours before her death on March 10 in the South Island.

The 24-year-old wrote six letters to individuals before she died and instructed that her mother read them all.

Monica read four including one to herself, but two addressed to academics at the university where Niki was studying a masters degree were withheld by the police and coroner Anna Tutton as part of the coroner's investigation into Niki's death.

Monica told the Weekend Herald in May it was Hindu custom that a deceased loved one's final instructions be carried out before their ashes could be put to rest.

She said she needed to read the letters before she could take Niki's ashes to India and it was breaking custom not to, a situation she found traumatising.

"I'm being prevented from fulfilling my daughter's last wishes and to put her to rest," she said in May. "So it is traumatic for me to live with this every day. It is just impossible to move on."

Monica, who was living in Canberra, Australia, at the time, asked police for the letters and appealed to the two staff they were addressed to.

She said the content was not as important as carrying out the wishes.

When that didn't work she tried the coroner's office and hired a lawyer to argue her case.

On September 5 she flew to Auckland. Police found her body later that day.

The office of chief coroner Deborah Marshall has confirmed she is now investigating both deaths.

A spokeswoman for the university said: "University staff who knew Monica, and her daughter, have been shocked and saddened at this tragic news. However, further comment is unable to be made as this matter is now before the coroner."

Mental Health Foundation chief executive Shaun Robinson said research showed people who lost close family members or friends to suicide were at significantly higher risk of suicidal behaviour, depression, anxiety, post-traumatic stress disorder and other negative health and social outcomes.

"Recent research suggests that each suicide leaves behind as many as 135 grieving people who knew the person who died," he said.

"Not all of these people will experience significant bereavement, but suicide will affect them in different ways.

"The risk of developing depression, anxiety or post-traumatic stress disorder increases with closeness to the person who died by suicide."

WHERE TO GET HELP:

If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.

OR IF YOU NEED TO TALK TO SOMEONE ELSE:

• DEPRESSION HELPLINE: 0800 111 757
• KIDSLINE: 0800 543 754 (available 24/7)
• LIFELINE: 0800 543 354 or 09 5222 999 within Auckland (24/7)
• NEED TO TALK? Free call or text 1737 (24/7)
• SAMARITANS – 0800 726 666
• SUICIDE CRISIS HELPLINE: 0508 828 865 (24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• YOUTHLINE: 0800 376 633, free text 234 or email [email protected]

There are lots of places to get support. For others, click here.