Memory Leak in SymMatrixBlock - c++

Question

I am trying to use a symMatrixBlock representation for the cloth simulation.
The following class stores a symmetric matrix nxn who's each element is a 3x3 matrix (represented as Mat33 class)
class SymMatrixBlocks
{
public:
int size;
int *rowstart;
std::vector<int> col_lookup;
std::vector<Mat33 *> matBlock;
bool bAllZero;
public:
SymMatrixBlocks(int size);
SymMatrixBlocks(const SymMatrixBlocks &src);
~SymMatrixBlocks();
void Zero(void);
SymMatrixBlocks& operator=(const SymMatrixBlocks &src);
SymMatrixBlocks& operator+=(const SymMatrixBlocks &src);
SymMatrixBlocks& operator-=(const SymMatrixBlocks &src);
SymMatrixBlocks& operator*=(double con);
Mat33* getMatBlock(int row, int col);
void SetDiag(DiagonalMatrix &src, DiagonalMatrix &ret);
void print();
Mat33* operator() (int row, int col);
};
inline const SymMatrixBlocks operator +(const SymMatrixBlocks &lhs, const SymMatrixBlocks &rhs)
{
return SymMatrixBlocks(lhs) += rhs;
}
inline const SymMatrixBlocks operator -(const SymMatrixBlocks &lhs, const SymMatrixBlocks &rhs)
{
return SymMatrixBlocks(lhs) -= rhs;
}
inline const SymMatrixBlocks operator *(const SymMatrixBlocks &lhs, double rhs)
{
return SymMatrixBlocks(lhs) *= rhs;
}
inline const SymMatrixBlocks operator *(double lhs, const SymMatrixBlocks &rhs)
{
return SymMatrixBlocks(rhs) *= lhs;
}
}
SymMatrixBlocks& SymMatrixBlocks::operator+=(const SymMatrixBlocks &src)
{
if (size != src.size)
return *this;
if (src.bAllZero)
return *this;
int i, j, start, length;
for (i = 0; i<src.size; i++)
{
start = src.rowstart[i];
length = src.rowstart[i + 1] - start;
for (j = 0; j<length; j++)
(*((*this)(i, src.col_lookup[start + j]))) += (*(src.matBlock[start + j]));
}
return *this;
}
Mat33* SymMatrixBlocks::operator() (int row, int col)
{
int i, start, l, length;
bAllZero = false;
if (row > col)
{
start = row;
row = col;
col = start;
}
start = rowstart[row];
length = rowstart[row + 1] - start;
for (l = 0; l<length; l++)
if (col_lookup[start + l] == col)
break;
if ((length != 0) && (l != length))
{
return matBlock[start + l];
}
else
{
for (l = 0; l<length; l++)
if (col_lookup[start + l] >= col)
break;
col_lookup.insert(col_lookup.begin() + start + l, col);
Mat33 *tempmat = new Mat33();
matBlock.insert(matBlock.begin() + start + l, tempmat);
for (i = row + 1; i <= size; i++)
rowstart[i]++;
return matBlock[start + l];
}
}
when I run the following line it gives memory leakage. Can anyone spot it out?
*tm1 = *df_dx * h; // all these are object of the SymMtrixBlocks class.