Former Brisbane real estate agent Gerard Baden-Clay had large debts and even approached a Queensland MP for a hefty loan before his wife’s death, his murder trial has heard.

The evidence came as a scientist testified that leaves found on Allison Baden-Clay’s body match those at her home, not the creek bank where she was found in April, 2012.

Three long-time friends of Baden-Clay’s told his trial they lent him a combined $199,000 in early 2011 to prop up his business.

The trio told the Brisbane Supreme Court they were approached for financial help after Baden-Clay’s west Brisbane real estate practice was hit hard by severe floods in January 2011.

“Without a further cash injection the business would have been in severe trouble,” friend Stuart Christ said.

“Simply, there was no cash in the bank to pay the bills.”

The trio said Baden-Clay’s interest repayments ceased after several months and the loans were never paid back.

Meanwhile, Queensland MP Bruce Flegg testified that he was friendly with Baden-Clay through the local chamber of commerce and the father of three had asked him for a $400,000 business loan in December 2011.

“He was quite adamant he was not looking for someone to put equity in (to his business), he was looking to borrow some money,” Dr Flegg said.

He said Baden-Clay again approached him for a loan in March the following year but after a short phone discussion Baden-Clay understood “it wasn’t going anywhere”.

The Member for Moggill also said he lived more than a kilometre from the Baden-Clay family home and heard two “distressing” female screams the night Mrs Baden-Clay was last seen alive.

Last week, the trial heard a former neighbour of the Baden-Clays testify about shouts and a scream she and her teenage daughter had made on the same night.

In other testimony, a botanist told the court he identified six plant species from leaf fragments police found entwined in Mrs Baden-Clay’s hair or on her body.

Gordon Guymer said he could find only two species at the Kholo Creek at Anstead, in Brisbane’s west, where her body was discovered but all six were found at the Baden-Clay family home.

And an expert in microscopic algae who examined Mrs Baden-Clay’s bone marrow and liver tissue concluded she didn’t drown.

Retired university professor Jacob John said if she had drowned he would have expected to find the algae, which is present in water, in her body tissues.

The court also heard from toxicologist Olaf Drummer who said it was unlikely she died from an overdose of the anti-depressant she was taking based on levels found in her system and also because the drug was not known to cause death in overdose.

Baden-Clay has pleaded not guilty to murder.

The trial continues.