You are a forensic accountant working for the SA Revenue Services 

$($SARS$).$ You received anonymous information that a certain Mr Botha has not declared all his income for the period $1$ March $2020$ to $28$ February $2023.$

You also received the following information:

Mr Botha earns a salary of R$550000$ per annum from the company he is working for. He has not had an increase in the last three years and, as a result, has decided to augment his salary by performing work outside his normal office hours.

In his spare time Mr Botha acts as an auctioneer at auctions of rare species of game. He is paid for his services and also earns commission on all the game that is sold. However, Mr Botha has only declared the income from his salary to SARS and not the income from his business as an auctioneer. You are unable to obtain any information about the number of auctions Mr Botha has facilitated or the commission that was paid to him. The organisers of these auctions pay him in cash on the day of the auction and no records are kept.

According to Mr Botha's tax return for the year ending $28$ February $2020,$ he owns furniture and fittings amounting to R$225000$ and a VW Golf $4\mathrm{.}6,$ which he bought for R$465000$ on $5$ September $2017.$ According to the VW branch in Sandton, the vehicle was worth R$445000$ on $1$ March $2020$ and R$195000$ on $28$ February $2023.$

During a search$-$and$-$seizure operation on $28$ February $2023,$ the following was established:

$$ An amount of R$372000$ in cash was discovered in a safe in Mr Botha's home.

$$ A number of gold jewellery items were also found in the safe, together with the purchase invoices. $$ A collection of antique weapons was also found.

A valuator of antique weapons is called in to value the weapons. The valuator finds the value of the weapons to be R$2983000$ in total. Mr Botha indicates that he bought the antiques with money that he inherited from his father who passed away in $2020.$ You are able to obtain the receipts for all the weapons from Mr Botha$$s study. The invoices show that he paid a total of R$2000000$ in cash for the weapons.

The receipts of all the jewellery were found in a file in Mr Botha's study. The jewellery was bought from local jewellers and everything was paid for in cash. The total purchases amounted to R$234000.$ The jewellery was valued at R$212000$ on $28$ February $2023.$

Mr Botha bought his home in Bryanston on $18$ September $2016$ for R$3995000.$ The market value of his home was R$4250000$ on $1$ March $2020$ and R$4350000$ on $28$ February $2023,$ as determined by an independent valuator. According to his bank, Savings Bank, on $1$ March $2020$ Mr Botha owed R$3800000$ on his bond, and on $28$ February $2023,$ R$3100000.$ He paid a total amount of R$900000$ towards his bond for the period, which included capital redemption as well as interest.

Information from the Masters office indicates that Mr Botha inherited R$2500000$ from his father, who passed away in November $2020.$

On $5$ August $2022,$ Mr Botha bought a BMW from the Sandton BMW branch for an amount of R$1550000,$ paid in cash. The car was valued at R$1545000$ on $28$ February $2023.$

Mr Botha has a current account with Savings Bank; on $1$ March $2020$ the balance was R$23000$ and on $28$ February $2023,$ R$27000.$ According to his credit card statements from Bleep Bank, he owed R$48000$ on $1$ March $2020$ and R$52000$ on $28$ February $2023$ on his credit card. He spent R$760000$ over the three$-$year period on living expenses, including the R$52000$ which is still outstanding on $28$ February $2023.$

According to a statement discovered in Mr Botha's study from a local travel agent, it appears that Mr Botha has been travelling overseas regularly. A statement dated $28$ February $2023$ indicates that Mr Botha owed the travel agency R$33000$ for flights and accommodation that were booked on his behalf. Information obtained from the travel agency furthermore reveals that Mr Botha has spent R$194000$ on overseas travel in the last three years, inclusive of the unpaid R$33000.$

All other non$-$taxable deductions, not mentioned above, for which invoices could be found in Mr Botha's study, amount to R$435000.$

REQUIRED 

$1\mathrm{.}1$ Calculate the amount of undeclared taxable income for Mr Botha for the period $1$ March $2020$ to $28$ February $2023,$ using the asset method of the net$-$worth analysis.

$1\mathrm{.}2$ You decide to subject Mr Botha to a polygraph examination in order to obtain evidence to prove that he has not declared all his taxable income. You are planning to use this information in a criminal court to prove your case against Mr Botha. Discuss whether you may subject Mr Botha to a polygraph test and whether the evidence so obtained will be admissible in court.