A couple found dead after sending the BBC a letter criticising UK laws on assisted suicide were "frightened unnecessarily", a pro-life groups says.
Dennis and Flora Milner, aged 83 and 81, were found dead in their home in Newbury, Berkshire, on Sunday.
Their letter said they wanted to highlight the "human dilemma" stopping people from legally ending their lives with their loved ones around them.
ProLife Alliance blamed what they said were unfounded fears about old age.
Chair Dominica Roberts told BBC News pro-euthanasia groups "frightened people unnecessarily about how the end of their lives will be".
"There are far more people now who are afraid of being incapacitated and in pain, but the fears are less grounded," she said.
"Pain relief is better and the solution is to plan better care, not a quick fix. Britain leads the world in end of life care."
She added that no-one had a "right to die with people around you and there is no right to die".
Other pro-life groups also criticised the deaths.
SPUC Pro-Life said: "The police should investigate the circumstances of this couple's apparent suicide to establish whether any other person was involved in the deaths.
Assisted suicide laws
Anyone helping someone kill themselves in England or Wales could face 14 years in prison
In Scotland and other European contries the law is less clear, some have more liberal laws
In Switzerland, organisations like Dignitas help people end their life
To date, more than 100 UK citizens have travelled to Dignitas to end their life.
"We would like them to look into issues such as possible social or financial pressures the couple might have been under.
"We will be writing to the Director of Public Prosecutions urging him to ensure that the matter is fully investigated."
But Dignity in Dying said the case highlighted some people's deep concerns about suffering unnecessarily at the end of life, and the lack of a safeguarded choice.
"People are burying their heads in the sand if they think people won't continue to take these drastic actions," a spokesman said.
"We acknowledge that with good access to good quality social and end of life care, most people will have what they consider to be a dignified death.
"But there are those that will not."
He said an assisted-suicide law would comfort many people because they would know they had an option should they ever feel in that position.
The letter was delivered to BBC South on Tuesday, accompanied by a statement that appeared to be signed by both Mr and Mrs Milner.
In it Mr Milner talked about his campaign to change the law to give people the right to choose how and when to end their lives.
He said he and his wife had "chosen to peacefully end our lives" because "to force the issue beyond this point would mean for us a living death".
Chrissy and Nigel support their parents' decision to take their own lives
He added that arranging their deaths "so that it does not fail" had been "very difficult and traumatic for us".
"This need not and should not be the case."
The couple's son, Nigel, and daughter, Chrissy, said their parents were very clear in their views about a need for a change in the law on euthanasia, and both endorsed their parents actions.
They said they knew about the suicide pact but did not know when they planned to kill themselves.
Thames Valley Police said they were treating the deaths as unexplained but not suspicious.
Toxicology tests are being carried out to confirm how they died.