Maria de Villota’s family is not ruling out legal action after more details of her 2012 Marussia crash emerged.
Last month, Britain’s Health and Safety Executive said action would not be taken against the backmarker team even though the 33-year-old Spaniard died 15 months after suffering horror injuries in the crash at Duxford Aerodrome.
"To date we are still waiting to know the contents of the report and, consequently, the actual results of their research," the family, including her father and former F1 driver Emilio de Villota, declared a month ago.
Now, some of the details of the official crash report have been obtained by the BBC, following a Freedom of Information request.
One of the findings was that de Villota, who lost an eye in the crash, had been sent instructions about driving the car but nothing "about stopping the car or which gears should be selected" for that, the BBC said.
The investigation found that the driver locked the wheels when slowing down, but the car began "fighting" de Villota as it automatically maintained revs due to the idle control system.
She was then "pushed" by the car into the unusually-large loading ramp whose position "created the risk of injury", the report added.
It also said "nothing happened" when de Villota tried to unlock the clutch and disengage the gears.
After the BBC details emerged on Monday, the de Villota family revealed in a statement that it received the official investigation report last week.
"The data shows a number of irregularities occurred on that day," Spanish media reports quote the statement as saying.
The family said the irregularities include the "questionable position" of the truck with the open ramp, and the "lack of logistical and technical information" given to de Villota and "absence of basic safety guidelines".
"The report confirms that Marussia F1 Team, in assessing the risks of the test, did not consider its own facilities (including the position of the truck and its ramp) and the car design."
The statement said "family lawyers are analysing in detail the contents of the report in order to define the next steps, without discarding the commencement of actions for damages".
Marussia, now competing in F1 as Manor, did not comment.